In recent years, a technique of attaching an input device referred to as a touch panel or a touch sensor to a display surface side of a display device and detecting and outputting an input position when input operations are performed by contacting the touch panel with a finger or an input tool such as a touch pen has been known. Since such display devices including a touch panel do not require input devices such as a keyboard, a mouse and a keypad, they are widely used in portable information terminals such as mobile phones in addition to computers.
One detecting method for detecting contact positions at which a finger or the like has contacted the touch panel is the electrostatic capacitance method. In an electrostatic capacitive touch panel, a plurality of capacitive elements each made up of a pair of electrodes disposed to be opposed to each other with a dielectric layer interposed therebetween, that is, a driving electrode and a detecting electrode are provided in a plane of the touch panel. Then, the input positions are detected by utilizing the characteristics that the electrostatic capacitance of capacitive elements changes when performing input operations by contacting the capacitive elements with a finger or an input tool such as a touch pen.
For example, Japanese Patent Application Laid-Open Publication No. 2010-197576 (Patent Document 1) describes a touch panel in which measures for making transparent electrode patterns invisible are taken. Further, Japanese Patent Application Laid-Open Publication No. 2011-059771 (Patent Document 2) describes a mesh-like conductive pattern including mesh patterns which are at least partially separated and have superior invisibility even at discontinuous portions, and a base material and a touch panel member having conductor layer patterns including the mesh-like conductive pattern.